Various goods and products, such as furniture, vehicles, construction materials are susceptible to damage by oxygen, light, water or the like. These various goods and products are often coated with coating composition for protection and functionalization. Solvent-based coating compositions have long been used in surface finishing due to their favorable coating characteristics. However, these solvent-based coating compositions are associated with hazardous volatile organic chemicals, heavy metals and other environmental-unfriendly materials that pose serious health and environmental concerns. As a result, the coating composition industry has now turned its focus towards developing a water-based coating composition coat.
Current aqueous-based environmental coating compositions are generally based on high molecular weight resin, modified polyurethane and acrylic materials in order to reduce the content of organic solvent. Kansai Paint Co. Ltd. developed a product based on water dispersible acrylic polymer particles (U.S. Pat. No. 5,322,865 and U.S. Patent Application Publication 2009/0099298) and polyurethane (U.S. Pat. No. 6,787,190). In U.S. Pat. Nos. 5,747,558 and 5,972,425, water-dispersible resins for coating are disclosed. Nevertheless, conventional water-based coating compositions suffer from weak film-coating performance, long-drying time, and limited functional and chemical tunability. Studies have been carried out to investigate water-based composition with better coating film performances, such as mechanical properties and water resistance. Iribarren et al. (Materials and Corrosion, Volume 57, Issue 9, Pages 683-688, 2006) teaches that polyurethane resin-based coating composition modified by a conducting polymer improves resistance to corrosion. Sun et al. (Journal of Coatings Technology and Research 2012) teaches an acrylic-based fast drying water-resistant coating composition made up of crosslinkable monomers polymerized with acrylate, nano-silica blended latex, polyfunctional amine, pigments and filler. Recently, the application of silica and other inorganic nanosols has been found to be valuable in functionalization of wood surfaces (Mahltig et al., Fuctionalising wood by nanosol application, Journal of Material Chemistry, 2008, volume 18, pages 3180-3192). Nonetheless, the existing water-based coating compositions only possess satisfactory coating performance as compared to solvent-based coating compositions. Therefore, there is a need for a new water-based coating composition with improved film coating performances.
The present invention describes a new generation of environmental water-based coating composition based on organosilica with enhanced properties over the existing water-based compositions. The present coating composition demonstrates improves mechanical strength, high chemical tunability for functional modification, high surface hydrophobicity and shortened drying time. The high chemical tunability of the present invention means that attractive properties can be easily added to the coating composition by incorporating desired functional additives.